AndrewRayCode / federation-test

Using Node 16/latest

Install

npm install

Then start services

npm run start-services

Then start the gateway in another terminal

npm run start-gateway

Then open http://localhost:4000

Verify you can run this query:

query Me {
  me {
    id
    name
  }
}

Now open services/new/index.js and update the typedefs to add:

  extend type Member @key(fields: "id") {
    id: ID! @external
    name: String
  }

According to the documentation the service that defines a field last should continue to resolve it. Instead, the gateway raises a composition error:

This data graph is missing a valid configuration. [new] Member.name -> Field "Member.name" already exists in the schema. It cannot also be defined in this type extension. If this is meant to be an external field, add the @external directive.

If you run the same query again in the playground, the whole query errors out:

"message": "This data graph is missing a valid configuration. More details may be available in the server logs."

Using this local demo I am unable to validate the claim the docs make that apollo server gracefully handles field conflicts